view mercurial/rewriteutil.py @ 43813:5a9e2ae9899b

fuzz: use a more standard approach to allow local builds of fuzzers

This is taken from the (improved since we started fuzzing) guide on ideal
integrations. Rather than have our own wonky targets for building outside the
fuzzer universe, we have a driver program we carry along and use when we're
not using LibFuzzer. This will let us jettison a fair amount of goo.

contrib/fuzz/standalone_fuzz_target_runner.cc is
https://github.com/google/oss-fuzz/ file
projects/example/my-api-repo/standalone from git revision
c4579d9358a73ea5dbcc99cb985de1f2bf76dcf7, reformatted with out
clang-format settings and a no-check-code comment added. It allows
running a single test input through a fuzzer, rather than performing
ongoing fuzzing as libfuzzer would.

contrib/fuzz/FuzzedDataProvider.h is
https://github.com/llvm/llvm-project/ file
/compiler-rt/include/fuzzer/FuzzedDataProvider.h from git revision
a44ef027ebca1598892ea9b104d6189aeb3bc2f0, reformatted with our
clang-format settings and a no-check-code comment added. We can
discard this if we instead want to add an hghave check for a new
enough llvm that includes FuzzedDataProvder.h in the fuzzer headers.

Differential Revision: https://phab.mercurial-scm.org/D7564

# rewriteutil.py - utility functions for rewriting changesets
#
# Copyright 2017 Octobus <[e-mail]>
#
# This software may be used and distributed according to the terms of the
# GNU General Public License version 2 or any later version.

from __future__ import absolute_import

from .i18n import _

from . import (
    error,
    node,
    obsolete,
    revset,
)


def precheck(repo, revs, action=b'rewrite'):
    """check if revs can be rewritten
    action is used to control the error message.

    Make sure this function is called after taking the lock.
    """
    if node.nullrev in revs:
        msg = _(b"cannot %s null changeset") % action
        hint = _(b"no changeset checked out")
        raise error.Abort(msg, hint=hint)

    if len(repo[None].parents()) > 1:
        raise error.Abort(_(b"cannot %s while merging") % action)

    publicrevs = repo.revs(b'%ld and public()', revs)
    if publicrevs:
        msg = _(b"cannot %s public changesets") % action
        hint = _(b"see 'hg help phases' for details")
        raise error.Abort(msg, hint=hint)

    newunstable = disallowednewunstable(repo, revs)
    if newunstable:
        raise error.Abort(_(b"cannot %s changeset with children") % action)


def disallowednewunstable(repo, revs):
    """Checks whether editing the revs will create new unstable changesets and
    are we allowed to create them.

    To allow new unstable changesets, set the config:
        `experimental.evolution.allowunstable=True`
    """
    allowunstable = obsolete.isenabled(repo, obsolete.allowunstableopt)
    if allowunstable:
        return revset.baseset()
    return repo.revs(b"(%ld::) - %ld", revs, revs)